Analysis and Design of a Zeta Converter Based Three-Phase Switched Mode Power Supply

Telecom power supplies are mostly rich in harmonics which leads to poor power quality. Analysis, design and performance of a three-phase power factor corrected (PFC) isolated zeta DC-DC converter based 9 kW power supply (PS) meant for telecom tower is carried out here for power quality improvement. High power rating of the proposed power supply is achieved by using series connection at the secondary windings of the high frequency transformers (HFTs) of the zeta DC-DC converters. This arrangement eliminates the third harmonic component in the ac mains current which is beneficial to the improvement of the power quality. The proposed power supply based on zeta DC-DC converter is designed, modeled and simulated in discontinuous conduction mode (DCM) to investigate its steady state behavior and dynamic behavior. The supply current is close to sinusoidal with low total harmonic distortion (THD) and nearly unity power factor (PF). It is determined that the various power quality indices are within international standard limits at full as well as light load.